shrinking an hfs+ partition

"The issue is that the data is spread across the partition with the free space required to shrink it located in between data. There are a couple options (at least):

iPartition by Coriolis Systems. Works flawlessly. It comes with a Lite version of their iDefrag, which can compact the data and move the free space to the end of the drive. I never tried gparted but I didn't see any positive results online using it for HFS+ on Macs. Not free.
Clone the drive onto an external or something, and then clone it back to the original. I've never tried this but I've read that it basically puts all the data at the beginning of the partition, allowing you to use Disk Utility to shrink it."